Process of making benzanthrone and its derivatives



Patented Sept. 28, 1926.

UNITED STATES 1,501,319 PATENT OFFICE.

FERDINAND 1V. PECE, 0F PENNS GROVE, NEW JERSEY, AND JOHN H. SACHS, OF WIL- MINGTON, DELAWARE; ASSIGNORS T0 E L DU FONT DE NEMOURS dz; COMPANY, OF WILMINGTON. DELAWARE. A CORPORATION OF DELAWARE.

PROCESS OF MAKING BENZANTHRONE AND ITS DERIVATIVES.

F0 Drawing.

This invention relates to the production of benzanthronc and its derivatives, and com prises heating anthracenc or one of its derivatives, such as a-nthranol, with glycerine and a condensing agent in the presence of an oxidizing agent.

The method heretofore generally used in preparing benzanthrone is described in EX- ampl 2 of U. S. Patent No. 787859. to R. H. Scholl and O. Bally, according to which anthranol is suspended in sulfuric acid (82% strength), glycerinc added, and the mixture heated until the reaction is cdmpic-ted. We have now discovered that this reaction is facilitated and accelerated by the action of an oxidizing agent, and particularly a mild oxidizing agent such as nitrobcnzene and 'anthrnquinone. The use of anthraquinone for this purpose is particularly advantage us in view of the fact that in acting as an oxidizing agent, it 15 reduced to anthranol, which then takes art in the condensation, the intr duction 0 an extraneous material into the reaction mixture being thereby avoided.

The yield of benzanthrone is substantially increased by using an oxidizing agent in accordance with our invention, being in some cases as much as 88% of the theoretical as compared with the 6f 70% yield obtainuble with the process as heretofore practiced.

According to our preferred 'method of operating, we start with a given weight of nnthr'aquinone and reduce a portion only of this anthraquinone to anthranol, and then when the reduction has proceeded to the proper ratio of anthronol end anthraquinone begin the condensation. The same results may be obtained by preparing the anthrnnol separntely and mixing this withthe proper ratio of anthraquinone. The best results in the way of yields are obtained with 3540 parts of anthrunol to 60-65 parts of nnthrequinone, the yield hein 8588%. With 100% anthrnnol, the yield is around 7 1% and with anthrenol and nitrohenzenc the ield is 75--80% Aside from I16 increase in yield ohtnined by the use of anthraquinone as an oxidizing agent, is the advantage of obtaining a relatively large amount of bcnzunthrone from a small amount of unthrginol. The reduction of anthruquinone to unthrnnol Application flied August 23. 1924. Bei'lal Ru. 733.839.

mixture is warmed to 40 C. and 30 parts of a mixture of 50 parts of water and '50 parts of glycerine are added in the course of onehalf hour, the temperature being allowed to rise to 90 C. during this addition. The mixture is then heated in the course of an hour and a half to 12 C. at which point it is maintained for three hours. It is then cooled to 60 C. and drowned in 1000 parts of water. The precipitated crude'benznnthrone is filtered ofi, weshedwcid free and then boiled u with 500 arts of a 1% solution of caustic soda. e mass is filtered hot, the cake of benzanthrone is washed with hot water until alkali free and is then dried. The yield is 80% of the theory.

II. A mixture of 6 parts of anthraquinone and 4 parts of anthranol are dissolved in 220 parts of 95% sulfuric acid at room temperature. The mixture is warmed t8 40 and at this point the addition of 3 parts of a. mixture 50.parts of water and 50 parts of glycerme is begun. The procedure from tins point is similar to that in Example I. i

III. 10 parts of anthrequlnone are dissolve'dat room tern reture in 220 parts of 95% sulfuric aci and the solution is warmed to 40 C. Aluminum powder is then added until a test portion shows that 40% of the anthraquinone has been reduced. For this amount of reduction approximately 2 part", of aluminum are re quired. The addition of 30 parts of a mixture of 50 arts of water and 50 parts of glycorirne is then begun The procedure rorn this point is similar to that in EX- ample I.

In place of enthraquinone in the above examples, various other substances having a. moderate oxidizing action may he used, but we prefer nnthrnquinono for the reason stated above. Other conditions specified in Example I above, such as durations of the reaction periods, and temperatures employed, may of course be varied to a certain extent without departing from our invention.

We claim 1. The process of producing bcnzanthrones which comprises condensing an antbracene compound free from nitrogen with glycerine in the presenceof an oxidizing agent.

2. The process of producing benzanthrone which comprises condensing anthranol with glycerine in the presence of an oxidizing agent.

3. The process of producing benzanthrone which comprises condensing anthranol with glycerine in the presence of sulfuric acid and of an' oxidizing agent comprising anthraquinone.

4. The process of producing benzanthrone which comprises heating an anthranol compound with glycerine and strong sulfuric acid in the presence of an oxidizing agent.

5. A process as defined in claim 4 in which the oxidizing agent is anthraquinone.

6. A recess :15 defined in claim 4 in which the oxi izing agent is an aromatic compound having a mild oxidizing action.

7. The process of making benzanthrone which comprises heating, eventually to about 120 CL, a mixture containing anthrano], glycerine, sulfuric acid, and anthraquinone. and recoverin the benzanthrone resulting from the reaction thus induced.

8. The process of producing benzanthrone which comprises heating a mixture eon taining sulfuric acid, glycerine, four parts of anthranol, and about 6 parts of anthraquinone, and recovering benzanthrone resulting from the reaction thus induced.

9. A process as defined in claim 8 in which the mixture is heated to a temperature of about 120 C. for about 3 hours.

10. The process of making benzanthrone which comprises dissolving four parts of anthranol and about six parts of anthra. quinone in about 220 parts of 95% sulfuric acid, gradually adding about parts of a mixture of about equal parts of water and glycerine to the sulfuric acid solution at a temperature ranging from 40 C. at the start to about 90 C. when the addition of gl vcerine is completed, heating the resulting mixture at a temperature above 90 C. but

below that at which undesirable decomposition of the reagents would occur, until the conversion of anthranolto benzanthrone is the mass,.

practically completed, coolin drowning it in water, and filtering and washing the precipitate.

In testimony whereof we affix our signatures.

FERDINAND lV. PECK. JOHN H. SACHS.

extent without departing from our invention.

We claim;

1. The process of producing bcnzanthrones which comprises condensing an anthracene compound free from nitrogen with glycerine in the presence of an oxidizing agent.

2. The process of producing benzanthrone which comprises condensing anthranol with glycerine in the presence of an oxidizing agent.

3. The process of producing benzanthrone which comprises condensing authrauol with glycerine in the presence of sulfuric acid and of an oxidizing agent comprising anthraquinone.

4. The process of producing henzanthrone which comprises heating an anthranol compound with glycerine and strong sulfuric acid in the presence of an oxidizing agent.

5. A process as defined in claim 4 in which the oxidizing agent is anthraquinone.

6. A recess as defined in claim 4 in which the oxi izingr agent is an aromatic compound having a mild oxidizing action.

7. The process of making benzanthrone which comprises heating, eventually to about 120 C., a mixture containing anthranol, glycerine, sulfuric acid, and anthraquinonc, and recoverin the benzanthrouc resulting from the reaction thus induced.

8. The process of producing,' benzanthronc which comprises heating a mixture containin sulfuric acid, glyeerine, four parts of ant ranol, and about 6 parts of anthraquinone, and recovering bcnzanthrone resulting from the reaction thus induced.

9. A process as defined in claim 8 in which the mixture is heated to a temperature of about 120 C. for about 3 hours.

10. The. process of making benzanthrone which comprises dissolving four parts of anthranol and about six parts of anthra- %uinone in about 220 parts of 95% suluric acid, gradually adding about parts of a mixture of about equal parts of water and glycerine to the sulfuric acid solution at a temperature ranging from &0 C. at the start to about 90 C. when the addition of glycerine is completed, heating the resulting mixture at a temperature above 90 C. but

below that at which undesirable decomposition of the reagents would occur, until the conversion of anthranoito benzanthrone is practically completed, cooling the mass, drowning it in water, and filtering and washing the precipitate.

In testimony whereof we aflix our signatures.

FERDINAND W. PECK. JOHN H. SACHS.

Certificate of Correction.

It is hereby certified thht in Letters Patent No. 1,601,319, granted September 28, 1926, upon the application of Ferdinand W. Peck, of Penns Grove, New Jersey, and John H. Sachs, of \Vilmington, Delaware, for an improvement in Processes of Making Benzanthrone and its Derivatives, an error appears in thecprinted specifica' tion requiring correction as follows: Page 1, line 69, for 12 3 read 120 0.,-

and that the said Letters Patent should be read with this correction therein that the same may conform tothe record of the case in the Patent Otlice.

Signed and sealed this 12th day of October, A, D. 1926.

[sun] M. J. MOORE, Acting Commissioner of Patents.

Certificate of Correction.

It is hereby certified that in Letters Patent No. i,601,319 granted September 98, 1926 upon the'applicution of Ferdinand \V. Peck, of Palms Grove, New Jersey, and John H. Sachs, of \Vilr'nington, Delaware {or an improvement in 5 Processes of Making Benzanthrone and its Derivatives, an error appears in the )rinted specificat-ion requiring em'rection as follows: Page 1, line (M for 12 C read 120 0.; and that the said Letters Patent should be read with this correction therein that. the same may conform to the record of the case in the Patent Olliee.

Signed and sealed this 12th day of October A, D. 1926.

M. J. MOORE,

[sun] Acting Commissioner of Patents. 

